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Discussion Starter #1
I have heard that you can bypass the vacuum valve to keep the exhausts open at all RPMs. If so...

How do you do it?

Does it hurt performance or reliability at all?
 

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It will improve performance and I believe the way to bypass it, is by installing an aftermarket exhaust. Our sponsor DexM is also in the Mid-West and could help out I'm sure.
 

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Discussion Starter #3
I have heard it's simple...

As you know, on each side of the exhaust there are two pipes and one is closed below 5k rpm to keep the noise down around town. There are vacuume valves that control this and I know that they can be bypassed to keep them open all the time. I have heard it's simple to do this, but I do not know how. :-?
 

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I just happen to have a 360 exhaust system laying out in my shop. So I went out and grabbed the driver's side exhaust tips section, and am sitting here looking at it. With no vacuum to the cannister, the valve in the pipe is open. When vacuum is applied to the cannister the valve shuts. I verified this by running a wire through the pipe and out the tip. So it seems, if you want it open all the time...simply remove the vacuum hose. Be sure to put a plug or similar into the hose....you don't want a vacuum leak to the motor screwing things up. That's about all there is to it.
 

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Discussion Starter #5
That makes sense. I would assume the Modena exhaust is the same as the CS. I guess I could just start the car and see what the valve does while idling. :oops: Thanks, I'll give it a shot.
 

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chicagomiller said:
That makes sense. I would assume the Modena exhaust is the same as the CS. I guess I could just start the car and see what the valve does while idling. :oops: Thanks, I'll give it a shot.
No, they're completely different! The Modena butterfly valve is located at one of the the dual tail pipes and only opens after 4,000rpm. The CS valve is before the silencer and closes and bypass the silencer after 4,500rpm and becomes a straight-thro' system.
 

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chicagomiller said:
Is there a way to keep that valve closed all the time? If so, how do you do it? Would it hurt or help performance?
I may be wrong, but I think the engine is designed such that the exhaust gas flow is slowed down during low revs to help with the torque curve, once the rev is past 4,000 then the engine wants the power band to be up and that's why the butterfly valve opens.
 

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Discussion Starter #10
You were right Carguy. I was at my dealer today and all you do is disconnect and plug the hose to the vacuum valves on the second tips. They recommended that you cap off the valve also to keep dirt out of it and strap the hoses securely. They have done this on other 360 CSs and it does not hurt performance or reliability.

I got back to my shop and did it. WOW does it sound awesome!! Thanks for your tip...
 

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chicagomiller said:
You were right Carguy. I was at my dealer today and all you do is disconnect and plug the hose to the vacuum valves on the second tips. They recommended that you cap off the valve also to keep dirt out of it and strap the hoses securely. They have done this on other 360 CSs and it does not hurt performance or reliability.

I got back to my shop and did it. WOW does it sound awesome!! Thanks for your tip...
I am glad to hear you were able to get this altered the way you wanted. Did you happen to get a photo of the process or could you take a photo? I think this could make for a great Tech Tip in the "Tech" section of the site.
 

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You were a little wrong, the valve opens at 6300 rpm.

Stradale said:
I may be wrong, but I think the engine is designed such that the exhaust gas flow is slowed down during low revs to help with the torque curve, once the rev is past 4,000 then the engine wants the power band to be up and that's why the butterfly valve opens.
 

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I have the bypass-valves open on my 360 Modena and it sounds great now. Not only on higher revs but also on idle and low revs. Does not hurt power. In my opinion the best and cheapest way to improve the sound!
 

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chicagomiller said:
You were right Carguy. I was at my dealer today and all you do is disconnect and plug the hose to the vacuum valves on the second tips. They recommended that you cap off the valve also to keep dirt out of it and strap the hoses securely. They have done this on other 360 CSs and it does not hurt performance or reliability.

I got back to my shop and did it. WOW does it sound awesome!! Thanks for your tip...
PICTURES PLEASE !!! I really want to try this out but don't know which bit to take off and I don't want to do it wrong!!!

Trev
 

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OK I got brave...

I looked at the grey valves you can see from the engine bay, felt the pipe all the way down to the exhaust and pulled off the rubber section of piping connecting it to the exhaust butterfly valve... bunged up the ends of the pipe and tied back the rubber hoses so they didn't flap about. This all sounds very complicated but it took less than 2 minutes to do and simply ment pulling off a pipe by hand and connecting a bung...

Fired up the engine... immediately it already sounds louder and meaner..

Warm her up and give a few blips of the throttle! Wow, as Ferrari intended her to sound! Fantastic!! Just been for a few miles drive and I can say that it has woken up the beast. This is the best FREE thing you can do to a Ferrari! Takes a few minutes and saves the expense of a sports exhaust! I mean why bother when the factory one sounds this good after the mod. Prior to this it only sounded nice after 4,000 revs.. Also the main big plus point is that it only takes 2 minutes to put it back to stock!

Wonderful, just wonderful, thanx guys! Will take a couple of pictures and post them once I have charged the batteries for my digital camera!

Trev
A HAPPY MAN!
 
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